Block Calls: How to block certain area codes from calling in?

We use Ring Central for an after hours service for our customers. Customer calls our ring central number and is directed to my cell phone, if i do not answer, the customer leaves a voicemail that is distributed via email to a designated distribution list. The issue i am having is that we get 10-15 calls from "robots" daily which ring to my phone and sends the email to the distribution list. Is there a way to only accept calls from certain area codes (we only service a local area). Please help!

While you can do some limits on area codes, it's not really a good fix for your problem. From the business or technical side. Me personally, I have had the same cell-phone number for the last 10 years, several cities ago.

A much better solutions is to stop the unwanted calls to begin with.

When a customer calls after-hours, give them the option to "Press 1" to contact a person, or "Press 2" to leave a voicemail.

A "robot" will never press anything and just hang-up. It's after-hours, so your customers won't have a problem listening to the message and hitting 1 to get to a person.

Some of the recent threads on a Spam Calls, Ghost Calls, and Robocalls give good step-by-step instructions.